Cooling towers, boilers, pulp and paper chests and similar systems commonly utilize chemical treatments to inhibit corrosion, scale, bacteria growth and a host of other problems.
The chemical treatments are often delivered to the system site in large dispensing containers or pails from which the liquid chemical treatments are dispensed into the system. To aid in describing the invention, as discussed herein any system such as a cooling tower, boiler, pulp and paper chest or the like is referred to as a "receptacle" for the chemical treatment liquids. Chemical treatment liquids are typically dispensed into a receptacle in small quantities at predetermined time intervals until the dispensing container is emptied. The empty container is then replaced with a full container or refilled on site.
The transfer of chemical treatment liquid from a dispenser to a receptacle can be accomplished by filling a bucket or other vessel of known volume with liquid from the dispenser, carrying the liquid to a receptacle and pouring it into the receptacle. This transfer has the disadvantages that personnel carrying the liquid to the receptacle are exposed to splashes and spills and are subject to back injuries from lifting and carrying the liquid.
An alternative to manual liquid transfer from the dispenser to the receptacle is to connect a dispenser 2 to a receptacle 3 by pipes 4 and a pump 1 as shown schematically in FIG. 2. This transfer eliminates chemical exposure and back injury risk to personnel. However, in the event that pump 4 is inadvertently actuated or the electrical circuits which actuate pump 4 malfunction, leaving pump 4 actuated, it is possible for pump 4 to drain the dispenser 2 of liquid. This results in a large slug of treatment liquid entering receptacle 3 instead of small, measured volumes added over time. A large slug of treatment chemicals added to receptacle 3 can disrupt the desired chemical makeup within receptacle 3 and leaves the receptacle without any chemical treatment after the slug has passed.
Furthermore, pumping liquid directly into a receptacle is an inaccurate way to deliver a specific volume of treatment liquid since pump speed and efficiency changes over time, resulting in the volumetric delivery of a chemical treatment changing over time.
Thus, a need exists for an apparatus for transferring liquid from a dispensing container to a receptacle which eliminates exposure of personnel to chemicals, eliminates the danger of worker back injury, reduces the danger of dispensing container drainage due to accident or pump malfunction and delivers an accurate volume of liquid to a receptacle regardless of the pump performance over time.